Nick once put a UUC exhaust on his old 325. It lasted about 4 days till he got tired of the migraines.

Haven't touched a UUC product since then, but felt obligated to share.

@JLevi: that's quite irrelevant to an inquiry about the M3, and without even saying what year 325, then it's quite possibly not the same chassis or exhaust technology.

Our Corsa-based system are guaranteed "no drone". In fact, the patented RSC technology (RSC™ Technology - U.S. Patent # 5,952,625; 6,199,658; other patents pending) is infinitely beyond any other brand exhaust. Whereas all other systems are simple baffles or perf tube with packing, the UUC RSC systems use a computer-tuned acoustic analysis to absolutely eliminate any headache-causing drone sounds. In fact, when just steady-state cruising, it's one of the quietest systems around. However, it's very much a dual-personality design, very "Ferrari meets Nascar" sound when you get on the throttle.

Now you can have the ultimate exhaust performance and sound for your BMW without the intrusive in-cabin resonance found in other aftermarket exhaust systems. UUC's exhausts augmented with CORSA Performance technology deliver The Best Sound Around™ with RSC™ muffler technology, engineered to increase performance and eliminate annoying interior exhaust noise.

CORSA Redefines Exhaust Technology

The exclusive, patented RSC™ muffler design delivers the throaty exhaust tones that define your performance BMW on the open road. But inside, you will experience the quiet ride, that until now, you've only dreamed about.

CORSA has now made it possible with RSC™ - Reflective Sound Cancellation™ technology - using aeronautical and space age noise-suppression technology. Sound waves are reflected within the muffler case, producing a cancellation wave effect - with no flow restriction and without electronic devices!

The RSC™ muffler design features a pipe running straight through the muffler that incorporates a full 360-degree air gap that allows sound pressure waves to escape. The waves are channeled and then returned to the gap 180 degrees out of phase, canceling specific sound frequencies. All that remains is the clean, crisp sound of performance.

Automobile makers have been building mufflers for more than 100 years, and as the name muffler implies, the primary purpose of the muffler is to reduce noise emitted by the internal combustion engine. Muffler technology hasn't changed very much over the past 100 years. The exhaust is passed through a series of various-sized chambers in reactive-type mufflers, or straight through a perforated pipe wrapped with sound deadening material in an absorption-type muffler. Both types of mufflers have strengths and weaknesses. The reactive-type muffler is usually restrictive and prevents even the "good" engine sounds from coming through, but does a good job of reducing noise. On the other hand, most absorption-type mufflers are less restrictive, but allow too much engine noise to come through, especially at cruising speeds. And regardless of the packing material, absorption-type mufflers tend to get noisier with age.

More recently, automotive engineers have been experimenting with electronic noise suppression mufflers. A sound pressure wave 180 degrees out-of-phase is generated by an electronic device to cancel out a similar sound wave generated by the engine. It is an effective way of canceling noise without restricting flow. Unfortunately it is too costly and currently impractical for today's production vehicles. However, out-of-phase sound wave cancellation is the best technology to control engine noise.

CORSA's patented RSC™ technology reflects sound pressure waves within the muffler case to produce the same 180 degree out-of-phase wave cancellation effect, without flow restriction or electronic devices. It literally took the proverbial "rocket scientist" to come up with the design. An aeronautical engineer, with years of fluid flow, gas dynamics, thermodynamics, and acoustics experience on NASA and numerous other government projects, was employed to adapt some of this space-age noise-suppression technology to automotive mufflers. The result is the CORSA * Reflective Sound-Cancellation™ Technology.

When you refer to the above illustration, you will see an elegant design in simplicity, theory, and operation. Essentially, the RSC™ muffler design includes a pipe that runs straight through the muffler, almost as if there was no muffler in the system. However, in this straight through-pipe, there is a full 360-degree air gap that allows sound pressure waves to escape and travel down a channel. These waves are reflected back to the air gap where they arrive 180 degrees out-of-phase and cancels that particular sound frequency. Each CORSA RSC™ muffler cancels up to three primary resonance-producing sound frequencies. All that remains is the clean crisp sound of a healthy performance engine.

This technology enables CORSA engineers to tune each muffler to a specific vehicle by adjusting the size of the 360-degree air gap and the length of the pulse channels within the muffler for the best sound and least interior resonance. Initially, muffler design can be calculated using exacting acoustic and thermodynamic formulas. The final design specs are arrived at by using Real Time Spectrum Analysis equipment to analyze "real" sound at idle, acceleration, and cruise.

Once internal and external dimensions have been established for a specific vehicle, mufflers and exhaust systems are fabricated out of 100 percent stainless steel at CORSA's new 40,000-square-foot manufacturing facility in Berea, Ohio. The manufacturing process includes state-of-the-art equipment plasma, TIG welding, and hydroforming equipment. CORSA's RSC™ exhaust systems are resistant to corrosion and able to withstand high temperatures for long periods, enabling CORSA to offer a limited lifetime warranty - guaranteed to the original owner, against rust-through and corrosion, for as long as they own their vehicle.

As good as this theory sounds, what is really important is real-world performance. How good is it? It works the way a high-performance muffler really should...the amount of sound produced is directly proportional to the amount of throttle used. CORSA exhaust systems have been best described as "awesome sound at full-throttle and whisper-quiet cruise."

It's rare that any company invents a better "mousetrap" in an industry that has evolved over 100 years. But CORSA Performance is convinced, as are its satisfied customers, that no other high-performance muffler can compare to its RSC™ systems. As car enthusiasts get to hear the unique sound and experience the performance these mufflers deliver, this technology will be the standard of quality for performance mufflers in the future.

ummm... I assume that would mean the answer is yes it should work for a diffuser if the pics you have provided show the tips tucked all the way in. That would mean you can extend them out about one inch from pics you provided fitting most of the rear diffusers.

ummm... I assume that would mean the answer is yes it should work for a diffuser if the pics you have provided show the tips tucked all the way in. That would mean you can extend them out about one inch from pics you provided fitting most of the rear diffusers.

Correct, with the qualifier "should" strongly in place. Working on getting some diffuser samples here to compare.

Looks good though...nice to see an exhaust for the e90 that doesn't stick out too much

We offer two distinct part numbers, one for sedan and one for coupe/convertible as the exhaust fitments are actually different lengths. The E92 version's tip placement ends up the same as the E90 pictures.

Glad you like the tip positioning. I think the size/style/positioning is more "real world" and not oversized for the car.